Embodiments of the present invention are generally directed to enabling digital telephony and more particularly to systems and methods for providing digital telephone services via a portable media.
Packet switched networks (PSNs), most notably the Internet, have become increasingly accessible on a worldwide scale. Digital telephony service offers the promise of relatively inexpensive and feature-rich telephone service to users of PSNs.
One form of digital telephony, voice over Internet protocol or “VoIP,” has attracted significant market attention. A typical VoIP environment comprises a telephone that is connected to an analog-to-digital converter (ADC). The ADC converts analog voice signal from a plain old telephone (POT) phone and converts it into a compressed audio data stream. The ADC may be a standalone device that is connected to a computing device (e.g., a desktop computer, a laptop computer, or a personal digital assistant) or a component of a computing device (e.g., a sound card).
The computing device runs a software client (sometimes referred to as a “soft-phone client”). The softphone client presents the user a graphical interface that provides access to various telephone functions, for example, dialing, answering machine, call log, and number directory. The soft-phone client generates telephone-signaling information and converts the signaling information and compressed audio stream into packets. The soft-phone client may also use the sound card of the computer to provide two-way voice communication thereby dispensing with the need for the POT.
The softphone clients typically use the session initiation protocol (SIP) to establish call “sessions.” The softphone client also comprises one more audio compression codecs. Having more codecs allows the audio compression scheme to optimally utilize the network bandwidth.
A telephone connection may be established directly between two parties in a peer-to-peer configuration or service configuration through a central processor comprising a softswitch and a proxy server. The peer-to-peer configuration requires the two parties to know their respective Internet protocol (IP) addresses. In the service configuration, a softswitch, usually operated for a fee by a third party, can associate a telephone number with an IP address, and provides routing and signaling tasks to emulate services provided by the public switched telephone network (PSTN).
When a VoIP service subscriber initiates a call, the caller's telephone goes “off-hook” and the subscriber dials a called telephone number. The softphone client and the softswitch establish a session. The called telephone number is sent to the softswitch. If the call is directed to another VoIP service subscriber, the telephone number is translated to an IP address of the called party. The proxy server attempts to establish a session with the called party's softphone. If successful, the calling party's softphone and the called party's softphone exchange voice data packets. The ADC at each end of the call translates the incoming digital audio stream into analog signals that can be received by a POT or the sound card of the computer. When the call is completed (the telephone goes “on-hook”), and the softphone client sends a signal to the softswitch terminating the session.
A VoIP service subscriber may have access to the Internet at multiple locations using a variety of computing devices. Additionally, the VoIP subscriber may not have authority to install software on the computing device. For example, a VoIP subscriber may be using a computer at a place of employment, at the residence of a friend, or at an “Internet café” where Internet access is provided as a convenience or as a service. Currently, VoIP service access in these and similar situations would require that the softphone be installed and configured on the foreign computing device and, presumably, removed when the subscriber departs. The subscriber thereby risks disrupting the operation of the foreign computing device and exposing the subscriber's confidential information to capture by the foreign computer.
A VoIP subscriber may also have multiple computing devices from which VoIP calls can be made. Currently, each computing device is required to have a softphone installed and configured. The multiple softphone implementations each must be maintained individually. For example, updates to the software client and to the subscriber's preference must be installed on each softphone client so that the softphone clients are current.
What would be useful is a portable digital telephone softphone access module that may be operated from a computing device without significant reconfiguration of the operating system of the computing device.